A traveller has shared footage of an unusual train announcement to Twitter — and the creepy public warning has hammered home the frightening reality of China's controversial new Social Credit System for many Twitter users.

UK-based journalist James O'Malley was en route to Shanghai with his partner at the time of the announcement, and discreetly recorded it.

In the footage, a female voice can be heard over a PA system, threatening misbehaving commuters with punishment and a negative credit record.

"Dear passengers, people who travel without a ticket, or behave disorderly, or smoke in public areas, will be punished according to regulations, and the behaviours will be recorded in individual credit information system," the voice explains.

"To avoid a negative record of personal credit please follow the relevant regulations and help with the orders on the train and at the station."

O'Malley captioned the footage, "Here's a dystopian vision of the future: A real announcement I recorded on the Beijing-Shanghai bullet train."

The post has since been retweeted more than 18,000 times, with thousands weighing in on the confronting clip.

The footage is reminiscent of George Orwell's novel Nineteen Eighty-Four, in which citizens are under constant surveillance by the symbolic figure Big Brother.

Comparisons have been drawn between O'Malley's footage and the modern-day series Black Mirror. The first episode of season 3 follows Lacie as she works to maintain her social points and only associate with "high quality people".

On-screen character Lacie works hard to earn enough points to become a 'premium user' (Netflix)

China's Social Credit System is still relatively new, but like in so many dystopian works of fiction before it, seeks to assign each citizen with an individual score based not only on their lawfulness, but also their moral and social standing.

Early reports have found the regime has already banned millions of "untrustworthy" citizens from boarding flights and trains, according to ABC News, with plans to also freeze the assets of those branded "dishonest" by authorities.

Speaking with 9Honey Travel, O'Malley admits he was bemused when he heard the announcement.

"I'd read about the social credit system so understood some of the context for what might sound like a strange announcement.

"I remember thinking it was a stark reminder that though in many ways China resembles the west now — Shanghai is packed with massive shopping malls full of stores selling Cartier watches and Dunkin Donuts — it has all been achieved under a very different system with very different values to our own."

O'Malley said this announcement was the only time he'd noticed the new social credit system at play, but admitted that might only be because he didn't speak any Chinese dialects.

"What was striking to me though was the high level of passive surveillance. There were tonnes of instances where Chinese people would be expected to scan their national ID — such as at train stations, hotels, and even in order to get access to Tiananmen Square."

As well as punishing bad behaviour, the system seeks to reward good behaviours, such as donating blood or volunteering at a homeless shelter.

Twitter users were divided by the metro announcement, with some drawing comparisons with science fiction shows, and others wondering what all the fuss was about.